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Artificial habitat for cavity nesting birds can provide excellent opportunities for research and conservation efforts but may expose species to the negative impacts of warming ambient temperatures with climate change. Artificial nest boxes have been successfully used to monitor the breeding activity of the Cassin's auklet (Ptychoramphus aleuticus), a small burrow‐nesting seabird, on Southeast Farallon Island (SEFI) since 1971. Mean monthly ambient air temperatures on SEFI during the summer months have increased at an annual rate of roughly 0.03°C from 1971 to 2022, along with an increase in the number of extreme heat days and average maximum temperature, confirming a warming trend at this seabird colony. Given a projected increase in global temperature, we assessed the effectiveness of traditional wooden nest boxes vs. newer ceramic modules at buffering external ambient air temperatures in normal and extreme heat days across a gradient of microclimates on SEFI. Results from fitting linear mixed effects models indicated that, on average, internal temperatures of wooden and ceramic nests (of comparable size and shape) exhibited similar rates of deviation from ambient air temperature of approximately 0.15°C, even during extreme heat events. Ceramic modules did keep nest chambers cooler by approximately 1.2°C than wooden boxes during extreme events at the warmer, drier southern location of the island. Our results can help guide future efforts to design artificial nests that can effectively provide habitat for seabirds as ambient temperatures increase. [ABSTRACT FROM AUTHOR]

Highlights • Pre-breeding feather corticosterone (Cort) was not related to egg size. • Feather stable isotope ratios (δ15N, δ13C) were not related to egg size. • Results contradict previous studies conducted during poor oceanographic conditions. • Under good conditions, regulation of egg size may be independent of Cort and diet. Abstract The measurement of corticosterone levels in feathers (fCort) is gaining recognition as an effective means for describing links between stages of the annual cycle in birds. Many seabirds are especially good models for exploring these links, or carryover effects, due to their migratory behavior and reproductive investment in a single-egg clutch. Here, we measure fCort in Cassin's auklet (Ptychoramphus aleuticus) breast feathers at two colonies in British Columbia during 2011, a year of favorable oceanographic conditions, and examine its relationship with egg size. These feathers are grown at sea during the late winter period, 1–2 months prior to egg laying. Assuming that fCort provides some measure of nutritional stress and hypothalamic-pituitary-adrenal axis activity during feather growth, we predicted that fCort would be positively correlated with egg size via increased support for foraging activity during the nutritionally demanding molt stage. We also analyzed the δ13C and δ15N stable isotope content of breast feathers, measures commonly used to characterize seabird diet composition. Contrary to prediction, neither fCort nor stable isotope ratios were good predictors of egg size. Our results appear to conflict with two previous studies on alcids in which fCort and stable isotopes showed clear links with egg size; however, both studies were conducted in years when oceanographic and foraging conditions were poor. Under these conditions, upregulation of corticosterone may be needed to mediate the energetic tradeoffs between self-maintenance and reproduction, supporting increased foraging effort and thus increasing both the likelihood of reproduction and large egg size. However, when foraging conditions are favorable, we suggest that such tradeoffs and associated physiological constraints are minimized and regulation of egg size may be effectively independent of circulating corticosterone levels and diet type. [ABSTRACT FROM AUTHOR]

Individuals increase lifetime reproductive output through a trade-off between investment in future survival and immediate reproductive success. This pattern may be obscured in certain higher quality individuals that possess greater reproductive potential. The Cassin's auklet (Ptychoramphus aleuticus) is a long-lived species where some individuals exhibit greater reproductive ability through a behaviour called double brooding. Here, we analyse 32 years of breeding histories from marked known-age auklets to test whether double brooding increases lifetime fitness despite the increased mortality and reduced lifespan higher reproductive effort would be expected to incur. Multistate mark-recapture modelling revealed that double brooding was strongly positively associated with higher annual survival and longevity. The mean (95% confidence interval) apparent survival was 0.69 (0.21, 0.91) for individuals that executed a single brood and 0.96 (0.84, 0.99) for those that double-brooded. Generalized linear mixed models indicated individuals that attempted multiple double broods over their lifetime were able to produce on average seven times as many chicks and live nearly 6 years longer than birds that never attempted a double brood. We found that high-quality individuals exhibited both increased reproductive effort and longevity, where heterogeneity in individual quality masked expected life-history trade-offs. [ABSTRACT FROM AUTHOR]

Abstract: Climate change has exacerbated the occurrence of large‐scale sea surface temperature anomalies, or marine heatwaves (MHWs)—extreme phenomena often associated with mass mortality events of marine organisms. Using a combination of citizen science and federal data sets, we investigated the causal mechanisms of the 2014/2015 die‐off of Cassin's Auklets (Ptychoramphus aleuticus), a small zooplanktivorous seabird, during the NE Pacific MHW of 2013–2015. Carcass deposition followed an effective reduction in the energy content of mesozooplankton, coincident with the loss of cold‐water foraging habitat caused by the intrusion of the NE Pacific MHW into the nearshore environment. Models examining interannual variability in effort‐controlled carcass abundance (2001–2014) identified the biomass of lipid‐poor zooplankton as the dominant predictor of increased carcass abundance. In 2014, Cassin's Auklets dispersing from colonies in British Columbia likely congregated into a nearshore band of cooler upwelled water and ultimately died from starvation following the shift in zooplankton composition associated with onshore transport of the NE Pacific MHW. For Cassin's Auklets, already in decline due to ocean warming, large‐scale and persistent MHWs might represent a global population precipice. [ABSTRACT FROM AUTHOR]

In this study, the complete mitochondrial genome of Cassin’s auklet, Ptychoramphus aleuticus, was determined using Illumina sequencing. The complete mitochondrial genome of P. aleuticuss was 16,524 bp in length and encoded 13 protein-coding genes, 22 transfer RNA (tRNA) genes, and 2 ribosomal RNA genes. The overall nucleotide composition is: 30.8% A, 24.4% T, 30.6% C, and 14.2% G, with a total G + C content of 44.8%. By phylogenetic analysis using ML method, P. aleuticuss clustered with two Synthliboramphus species that belong to Alcidae.

To investigate the causal basis for patterns of seabird foraging distributions during breeding we integrated data from ship-board seabird and zooplankton surveys, aerial radio telemetry, and colony-based research programs. We examined the marine distributions of Cassin's Auklet ( Ptychoramphus aleuticus ) breeding on Triangle Island, in the Northeast Pacific off the coast of B.C., Canada using surveys conducted in 1999, 2000, and 2001. Concurrently, we sampled zooplankton at 16 stations along a cross shelf transect in the vicinity of Triangle Island. In 1999 and 2000, when populations of the preferred copepod prey Neocalanus cristatus were available at deep-water stations (1000–2000 m), the majority of the auklets were concentrated SW of the colony 40–75 km offshore and parallel to, but 35 −50 km beyond the shelf break in deep water (1200–2000 m). Birds did not fly farther out to sea to where prey was five times more abundant when N. cristatus could be found at lower abundance levels, closer to the colony. In 2001, N. cristatus were virtually absent at the deep-water stations, likely as a result of massive salp (family Salpidae) aggregations which may have consumed and displaced the seabirds’ preferred prey. We demonstrate that while birds were still able to locate and provision chicks with N. cristatus in 2001, they had to forage farther away from the colony in order to do so. Our telemetry results are generally consistent with analyses of at-sea distributions of Cassin's Auklets derived from ship-board surveys (1990–2010) both of which have contributed to the design of the proposed Scott Islands marine National Wildlife Area, the first of its kind in Canada. [ABSTRACT FROM AUTHOR]

Some plant communities develop as a result of chemical and physical perturbations by burrowing seabirds and are affected when those activities are reduced. Declines in burrow density and population size of Cassin's Auklets Ptychoramphus aleuticus at their largest breeding colony on Triangle Island, British Columbia, from 1989 to 2009, have been associated with decreases in tufted hairgrass Deschampsia cespitosa and increases in salmonberry Rubus spectabilis cover. These habitat changes may inhibit population recovery because Cassin's Auklets prefer tufted hairgrass and tend to avoid tall salmonberry for nesting. Surveys conducted in 2014 suggested a reversal in the population trend and provided an opportunity to compare vegetation changes during periods of increasing and decreasing burrow density. We hypothesized that decreased burrowing by seabirds allows salmonberry to invade and outcompete grass as the dominant cover and that increased burrowing reverses those trends. We related changes in vegetation composition to trends in burrow numbers within permanent plots established to monitor Cassin's and Rhinoceros Cerorhinca monocerata auklets on Triangle Island over a 25-year period. Trends in salmonberry cover and burrow numbers were negatively related. Decreases in salmonberry cover were directly correlated to increases in burrow numbers within plots, but, as found previously, increases in salmonberry cover were not directly correlated with decreasing numbers of burrows. There was no corresponding increase in grass cover with increasing burrow numbers. Vegetation damage and reduction due to seabird activities is probably more immediately apparent than establishment, spread or recovery of vegetation following seabird impacts. Our results confirm that biopedturbation by burrow-nesting seabirds negatively affects and reduces percent cover of woody shrubs, but only when burrow densities are increasing or high. At lower or declining burrow densities, seabird activities are inadequate to halt what may be the natural succession to mainly salmonberry cover on this non-forested island. [ABSTRACT FROM AUTHOR]

Eleven after-second-year Cassin's Auklets ( Ptychoramphus aleuticus), 10 of them females (91%), were killed when they collided with the lighthouse at Pine Island, Queen Charlotte Strait, British Columbia, in April (3 birds) and May (2 birds) 1976, and April 1977 (6 birds). This mortality of non-breeding Cassin's Auklets, which occurred late in the breeding season, possibly involved subadults visiting the Pine Island colony or other nearby colonies in Queen Charlotte Strait. Body weights ranged from 169 to 204 g, within the range of weights recorded for Cassin's Auklets visiting breeding colonies elsewhere during these months. The female bias in this sample, albeit statistically significant, is unexplained. [ABSTRACT FROM AUTHOR]

The article discusses research which investigated the diet of Cassin's Auklet or Pytchorampus aleuticus, burrow-nesting seabirds, at Langara Island in British Columbia from 1970 to 1971. Topics discussed include the status of the seabirds on the islands based on their occurrence and abundance in surrounding waters and breeding condition and diet.

ABSTRACT Hatching success in birds is influenced by the temperature and turning rate of the egg, but our understanding of the environmental factors that effect incubation temperatures and egg turning rates in birds is limited. Especially little is known of these effects for species that nest in burrows or crevices, such as the Cassin's auklet ( Ptychoramphus aleuticus). On Southeast Farallon Island, California, USA, a subset of the Cassin's auklet (hereafter auklet) population nest in artificial nest boxes. The nest boxes are above ground and made out of a single layer of plywood. Temperatures in unshaded nest boxes can increase significantly with high ambient temperatures (to >35° C). Shaded structures put on top of occupied nest boxes help mediate nest box temperatures, but the effects of elevated temperatures on auklet incubation behaviors and egg viability remain equivocal. We used egg data loggers to measure the temperatures and turning rates of auklet eggs in natural burrows, shaded nest boxes, and unshaded nest boxes on Southeast Farallon Island. Nest box (13.93 ± 1.26° C) and egg (37.43 ± 1.92° C) temperatures were highest and most variable in unshaded nest boxes. Mean hourly egg turning rate was 2.11 ± 2.02 turns/hour and turning rates were greater at night. Egg turning rates also varied with fluctuating nest and egg temperatures, being positively correlated with nest temperatures during the day and negatively correlated with egg temperatures during the night. Our results suggest that nest box design can influence incubation behaviors of breeding birds. As seasonal temperatures and the number of extreme heat events rise, understanding the impacts of temperature on auklets nesting in artificial nests can have positive implications for conservation and management of the species, such as implementing improved artificial nest box designs to prevent overheating of burrow nesting seabirds. © 2015 The Wildlife Society. [ABSTRACT FROM AUTHOR]

The article discusses a study which examines the population recovery of Cassin's auklet after the eradication of Black rats from Anacapa Island, California in November 2002. Findings show the detection of auklet nesting in six shoreline areas on the West and East Anacapa islets in 2012 and the discovery of 42 auklet nests from 2003 to 2012. It concludes the need of further nest monitoring to determine colony growth following the eradication.

We quantified the amount of plastic found in food loads delivered to nestlings in Cassin's Auklet ( Ptychoramphus aleuticus ), a small, zooplanktivorous seabird, on Triangle Island, British Columbia, in 1996–2016. The density of plastic in surrounding waters is moderately high, yet few food loads contained any plastic (3 of 850), and none more than two pieces. That result accords well with previous observations on the other four North Pacific auklets ( Aethia spp.), leading us to conclude that true auklets rarely transfer plastic to nestlings. However, many hatch-year Cassin's Auklets found dead in coastal British Columbia, Washington and Oregon during the mass mortality event of fall and winter 2014–15 had plastic in their ventriculi. We suggest that these plastic particles would have been obtained at sea after fledging, perhaps while the birds transited south through a region of high plastic density off the west coast of Vancouver Island, Washington and Oregon. [ABSTRACT FROM AUTHOR]

Oceanic plastic debris found in the digestive tracts of seabirds includes industrial plastic pellets and post-consumer user plastics. We examined whether the amount and type of plastic ingested by Cassin's Auklets ( Ptychoramphus aleuticus ) is changing by surveying the stomach contents of 171 Cassin's Auklets stranded along the Washington and Oregon coasts in 2014. We found that 41.5% of the birds contained plastic in their ventriculi, similar to values from the North Subarctic Pacific reported in the 1980s. Industrial pellets were found in 22.8% of our samples, and accounted for 28.1% of all the plastic pieces found. Industrial pellets tended to be larger than pieces of user plastic and accounted for 40.2% of total plastic weight. These industrial pellets were significantly smaller than those found in other species, suggesting either that Cassin's Auklets selected smaller plastic particles or that plastic was retained in ventriculi and worn down. [ABSTRACT FROM AUTHOR]

Crustal, slow deformation transients can be caused by fluid or magmatic intrusions, and by slow slip on faults. They can affect earthquake dynamics, if they occur close to or within seismically active zones. We here further develop, and test, a statistical method for detecting and characterizing seismicity anomalies that is only based on earthquake occurrence times and locations. We make use of this method to analyze the 2004–2013 seismicity at m c = 3.5 in the Aleutian subduction system, to find six statistically significant anomalies, with typical 1 day duration and 30 to 50 km size, that are likely related to slow deformation transients. They tend to be located in zones characterized by intermediate seismic coupling, and to mark the termination of past large to mega-thrust earthquakes. These anomalies account for a non-negligible ( 9 % ) part of the total activity, proving that non-stationary aseismic loading plays an important role in the dynamics of crustal deformation. [ABSTRACT FROM AUTHOR]

Aim Our aim was to investigate the influence of biogeographical barriers along the Pacific coast of North America on population genetic structure and gene flow using Cassin's auklet ( Ptychoramphus aleuticus) as a test case. Location We collected samples from 287 Cassin's auklets breeding along the Pacific coast of North America from the Aleutian Islands, Alaska, USA, to Baja California, Mexico. Methods We amplified a 706 base pair fragment of the mitochondrial control region and 11 microsatellites to obtain independent estimates of population genetic structure and gene flow among colonies using programs based on coalescent and Bayesian theory. We tested whether genetic differentiation was related to geographical distance between sampling sites, and whether gene flow has occurred between differentiated groups. Results We found two distinct genetic groups along the Cassin's auklet breeding range. These clusters matched the current subspecies designations, except that individuals breeding in the Channel Islands, California, were traditionally classified with the northern subspecies but were more genetically similar to the Baja California subspecies. Population genetic differentiation was not evident within either of the two genetic groups, despite large geographical distances between sampling locations. Evidence suggests that gene flow has occurred from the northern genetic group (Aleutian Islands to Southeast Farallon Islands) into the southern genetic group (Channel Islands to San Benito Island) since divergence, but gene flow may not have occurred in the opposite direction. These results suggest that a barrier to gene flow from south to north may occur at Point Conception. Main conclusions Although a relatively short geographical distance occurs between sampling sites of Cassin's auklets across Point Conception, individuals breeding north of Point Conception are genetically differentiated from individuals breeding in southern California and Baja California. Population genetic differentiation of the southern genetic group provides support for a role of a barrier to gene flow around Point Conception in generating biodiversity in this area. [ABSTRACT FROM AUTHOR]

We usedδ15N andδ13C analyses on blood drawn from zooplanktivorous Cassin's auklet (Ptychoramphus aleuticusPallas, 1811) on Triangle Island, British Columbia, over four years to address two questions: (1) do these seabirds systematically alter their trophic level and foraging habitat from one breeding stage to the next; and (2) do auklets select prey at the same trophic level and from the same foraging habitat to self-feed and provision offspring? Adult trophic level (inferred fromδ15N values) tended to be higher prior to egg-laying than during incubation, perhaps reflecting an abundant zooplankton biomass in early spring. Season-long declines inδ13C values suggested that the auklets foraged on the continental shelf early in the season, but thereafter increasingly used habitats seaward of the continental shelf-break to obtainNeocalanus cristatuscopepodites. Similarity in theδ15N andδ13C values of provisioning adults and nestlings suggested that adults consumed the same prey from those oceanic habitats to both self-feed and to provision offspring at the nest, a behaviour that may save time and energy. The results of this study show the dynamic nature of seabird foraging ecology and the utility of stable isotope analysis for assessing seasonal variation in the foraging ecology of oceanic species. [ABSTRACT FROM PUBLISHER]

We examined yearly rings from increment cores of conifers on two seabird nesting islands (one in the Lucy Islands and one in the Rankine Islands, British Columbia), to determine whether trees contained signatures of historical activity of seabirds. Ten conifers (primarily Sitka Spruce, Picea sitchensis), ranging from 56 cm to 127 cm diameter (average 90 cm) and ranging from 70 to 232 years in age (average 132 years of age), were cored across a 200-m gradient in densities of seabird burrows. At the site in the Lucy Islands, annual growth was highest (8-14 mm) in the trees with the highest seabird burrow densities and highest in the earliest rings (-1930), which were followed by a fluctuating reduction down to ~2 mm/year in the year 2000, but with a secondary elevated growth period in the 1970s. Adjacent control trees without seabird burrows had a growth rate of ~2 mm/year throughout the same period. At the site in the Rankine Islands, growth rates were also variable and exhibited a 10-15 year non-synchronous periodicity, with the highest growths in the location with high seabird burrow density. Nitrogen isotope signatures (ô15N), which are greatly elevated in seabird guano, ranged from minus 3.9% to 17.4% among tree rings (n = 245 rings) and were positively correlated to percentage nitrogen in rings, average ring growth, and burrow densities. Using these methods, we infer from our tree ring data that seabird activity declined on the Lucy Islands over a 70-year period and that the combination of growth, nitrogen isotopic signatures, and percentage nitrogen in tree rings as well a more detailed sampling grid of target and adjacent control trees will provide seabird biologists with additional tools for evaluating spatial and historical trends in seabird activity on forested islands. [ABSTRACT FROM AUTHOR]

The article examines the individual age and parental age effects in recruitment of Cassin's Auklet. It is revealed that in the multistate capture-mark-recapture method, individual age effects in recruitment and survival, but not in breeding inclination. It also examined the effects of parental-age on the return rate of young and on breeding performance through egg structure. It is inferred that young birds that successfully fledge offspring do not automatically deliver breeders.

Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article presents a study which examined the effect of extreme climate events on the adult survival rates of three auk species, namely, Cassin's Auklet (Ptychoramphus aleuticus), Rhinoceros Auklet (Cerorhinca monocerata) and Tufted Puffin (Fratercula cirrhata). The species breed in Triangle Island, British Columbia. The results of the study showed that only the Cassin's Auklet population is adversely affected with climate change.

Analysis of monthly coastal upwelling intensities revealed two seasonal and biologically relevant upwelling 'modes' in the California Current Ecosystem (CCE). The first mode reflected upwelling during the summer months and was characterized by low-frequency (multidecadal) processes, including significant (Po0.01) linear trends at some latitudes. In contrast, the second mode reflected wintertime upwelling and was defined by higher-frequency variability associated with the North Pacific High and El Niño Southern Oscillation events. These modes were compared with multidecadal time series of splitnose rockfish (Sebastes diploproa) otolith growth, yelloweye rockfish (S. ruberrimus) otolith growth, Chinook salmon (Oncorhynchus tshawytscha) scale growth, and indices of Cassin's auklet (Ptychoramphus aleuticus) and common murre (Uria aalge) reproduction in the central-northern CCE. In redundancy and correlation analyses, salmon growth and Cassin's auklet fledgling success associated with the summer upwelling mode while all other time series associated with the winter upwelling mode, indicating that CCE biology was differentially sensitive to these seasonal upwelling patterns. Thus, upwelling occurred in unrelated seasonal modes with contrasting trends, atmospheric forcing mechanisms, and impacts on the biology of the CCE, underscoring the importance of seasonality when evaluating ecosystem response to climate variability and change. [ABSTRACT FROM AUTHOR]

Santora, J. A., Ralston, S., and Sydeman, W. J. 2011. Spatial organization of krill and seabirds in the central California Current. – ICES Journal of Marine Science, 68: 1391–1402. The hypothesis that krill and krill–predator spatial organization and abundance co-vary interannually was tested by investigating the spatial organization of krill and planktivorous seabirds in the central California Current ecosystem over 5 years of varying oceanographic conditions, 2002–2006. To measure the abundance and distribution of krill, data were integrated from large-scale hydroacoustic surveys and station-based net samples, and these data linked to concurrent shipboard visual surveys of seabirds. Acoustically based estimates of the relative abundance of krill were correlated with net samples of Euphausia pacifica, suggesting that acoustic signals mainly reflected the distribution of this numerically dominant species. The distribution and abundance of krill displayed marked changes over years, but the characteristic spatial scale of krill and seabirds remained similar (1–4 nautical miles), confirming the hypothesis of covariance in spatial structure. Krill and the seabird species investigated showed similar habitat associations, i.e. the outer shelf and shelf–slope region, showing that the at-sea distributions of seabirds can provide information on the presence/absence of krill patches. The results also underscore the importance of measuring spatial organization as well as relative abundance in promoting better understanding of predator–prey and marine ecosystem dynamics. [ABSTRACT FROM PUBLISHER]

Abstract: In 2003 and 2004, we measured mercury concentrations and δ15N and δ13C values in the whole blood of adults of two species of seabirds, Cassin''s auklet (Ptychoramphus aleuticus) and rhinoceros auklet (Cerorhinca monocerata), during their prelaying, incubation, and provisioning periods. We also collected whole blood from the offspring of both seabirds. Among prey items, δ15N values were higher in fish than in crustaceans, while δ13C did not vary systematically between prey types. Mercury concentrations in prey showed little relationship with either stable isotope. In the zooplanktivorous Cassin''s auklet, year, reproductive stage, and δ15N and δ13C stable isotope values explained only 14% of the variation in mercury concentrations in adult blood, and none of these variables had a statistically significant effect. In contrast, these same variables explained 41% of the variation in mercury levels in the more piscivorous rhinoceros auklet, and all but δ15N values had statistically significant effects. Mercury concentrations in adult rhinoceros auklets were higher in 2003 than in 2004; higher prior to laying than during the incubation or provisioning periods; and increased with δ13C values — but in just one of two years. In both species, mercury concentrations were substantially higher in adults than in nestlings. Our results accord with previous studies in showing that mercury concentrations can vary among years, species and age classes, while the marked variation with reproductive stage is noteworthy because it is so rarely considered. Our results may help to explain the disparate conclusions of previous studies: while many factors influence mercury concentrations in marine predators, they apparently do so in a manner that defies easy characterization. We believe that there is a need for more studies that consider a range of physiological, ecological and behavioral factors that might affect mercury burdens in marine predators. [Copyright &y& Elsevier]

To better understand historical breeding distribution and population changes, breeding records from the period 1858-1910 (most pre-dating previous summaries) were assembled for 4 species of alcid in British Columbia (BC) and southeastern Alaska (SEAK), based on re-evaluation of museum specimens, literature, and unpublished sources. Earliest records for each species were: Ancient Murrelet (Synthliboramphus antiquus) at St Lazaria Island, SEAK, in 1866; Cassin's Auklet (Ptychoramphus aleuticus) at Forrester Island, SEAK, in 1897; Rhinoceros Auklet (Cerorhinca monocerata) at Pine Island, BC, in 1860; and Tufted Puffin (Fratercula cirrhata) at Mandarte Island, BC, in 1858. Other breeding records for these species in BC and SEAK prior to 1911 were reviewed, historical literature was clarified, and certain historical population changes of Rhinoceros Auklets and Tufted Puffins were examined. [ABSTRACT FROM AUTHOR]

The article investigates the effects of maximum extra load on the take off of high wing loading Leach's Storm-Petrel (Oceanodroma leucorhoa) and low-wing holding Casin's Auklet (Ptychoramphus aleuticus). Results suggest that the relation of maximum load to food transport and plumage wettability indicates that the Petrel and the Auklets maintain safety load margins of 31% and 8% of the extra load during take off respectively. Storm petrel margins suggest an enhanced flight performance while auklets allow for reduction of specific buoyancy during diving.

Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article discusses a study to determine the reasons behind the distribution of Cassin's Auklets, whose Latin genus is Ptychoramphus aleuticus, along Prince Island, off of Southern California. Researchers compared radiotelemetry with random location-associated habitats gleaned from remote satellites, looking into sea surface temperature, chlorophyll-a concentration, availability of zooplankton and those who fed off of them. As information on the last factor was not available, it was concluded that the other variables were key to their distribution.

Forecasting the ecological effects of climate change on marine species is critical for informing greenhouse gas mitigation targets and developing marine conservation strategies that remain effective and increase species' resilience under changing climate conditions. Highly productive coastal upwelling systems are predicted to experience substantial effects from climate change, making them priorities for ecological forecasting. We used a population modeling approach to examine the consequences of ocean climate change in the California Current upwelling ecosystem on the population growth rate of the planktivorous seabird Cassin's auklet ( Ptychoramphus aleuticus), a demographically sensitive indicator of marine climate change. We use future climate projections for sea surface temperature and upwelling intensity from a regional climate model to forecast changes in the population growth rate of the auklet population at the important Farallon Island colony in central California. Our study projected that the auklet population growth rate will experience an absolute decline of 11–45% by the end of the century, placing this population on a trajectory toward extinction. In addition, future changes in upwelling intensity and timing of peak upwelling are likely to vary across auklet foraging regions in the California Current Ecosystem (CCE), producing a mosaic of climate conditions and ecological impacts across the auklet range. Overall, the Farallon Island Cassin's auklet population has been declining during recent decades, and ocean climate change in this century under a mid-level emissions scenario is projected to accelerate this decline, leading toward population extinction. Because our study species has proven to be a sensitive indicator of oceanographic conditions in the CCE and a powerful predictor of the abundance of other important predators (i.e. salmon), the significant impacts we predicted for the Cassin's auklet provide insights into the consequences that ocean climate change may have for other plankton predators in this system. [ABSTRACT FROM AUTHOR]

The article presents a study which examines the effect of feather wetting on the critical penetration pressure of air in Xantus' Murrelet and Cassin's Auklet. It explores the process of the study which uses the feathers of the two species under to two conditions including dry and wet. It outlines the result of the study which reveals that dry feathers of both alcids did not resist air penetration in any pressure which illustrate that plumages could minimize heat loss.

Due to their marine habitats and distinctive foraging modes, seabirds face unique challenges with respect to flying that are negotiated differently by various species. One such challenge is taking off from the water with wet plumage. This study evaluated plumage wettability and takeoff performance in three seabird species: two wing-propelled divers with high wing loading, Cassin’s Auklet Ptychoramphus aleuticus and Xantus’s Murrelet Synthliboramphus hypoleucus; and Leach’s Storm-petrel Oceanodroma leucorhoa, a surface feeder with low wing loading. The plumages of the diving birds held less water than that of O. leucorhoa (~6.7% of body mass vs 9.5%). This difference is explained by O. leucorhoa’s surface to volume ratio being larger than that of the alcids. Furthermore, the alcids have afterfeathers larger than those of O. leucorhoa, which promotes a better insulation during diving. Examination of takeoff performance both before and after experimentally submerging the birds indicated that wingbeat frequency, speed and mass-specific power (peak and mean), and energy per wingbeat decreased in all species when plumage was experimentally wetted, whereas mean acceleration increased. O. leucorhoa was more strongly affected by wet plumage than the alcids, with a 32% of reduction in mass-specific energy per wingbeat compared to ≤25% in the alcids. Takeoff angle was reduced in alcids, but not significantly so in O. leucorhoa. Our results offer insights into the takeoff mechanics problems of wet seabirds given their differences in life history and morphology. [ABSTRACT FROM AUTHOR]

The article discusses a study on the impact of timing and parental quality on breeding success in a zooplanktivorous seabird. The subject used for this study was a Ptychoramphus aleuticus, also known as Cassin's Auklet. There is strength in the correlation of the shape index of the first eggs found in the burrows with that of the second eggs found in the same burrows.

The article examines the historical variation in the nestling diet of Cassin's auklet Ptychoramphus aleuticus breeding in British Columbia. It notes that within the region the nestling diet of the said species was composed of copepods and euphausiids, with fish contributing in some of the warmer seasons. It argues that Cassin's auklet nestling diet data reflect the temperature-related timing of Neocalanus prey availability to seabirds in surface water. It adds that poor reproductive performance is the biological consequence of trophic mismatch for Cassin's auklet.

The article discusses a study which describes the inter-specific, inter-annual, seasonal and age-related variation in the harvest of euphausiids by Cassin's auklets breeding in Triangle Island, British Columbia. The study explores whether the amount of three euphausiid species in nestling diets of Cassin's auklets vary among years and there are any systematic within-season patterns in the amount of these species delivered by parent auklets to their offspring. It also investigates whether there is an additive fitness benefit in including three euphausiids in the nestling diets. It claims that results provide insight into the effects of ocean climate on euphausiid biology in the California Current System (CCS).

We categorized and quantified the complete vocal repertoires of breeding adult auklets (Aethiini, 5 species) in their breeding areas to provide a baseline for comparative study of the structure and function of vocalizations within this monophyletic group of seabirds. We recognized 22 call types across species and 3-5 call types for each species. Calls were characterized by one to five frequency modulated, harmonically rich note types arranged sequentially in varied combinations. Frequency attributes varied more than temporal attributes within and across species. Repertoires and display complexity of nocturnal and diurnal species did not differ consistently. We recognized two major forms of vocal display: alternating arrangement of note types (Cassin's Auklet [Ptychoramphus aleuticus] and Parakeet Auklet [Aethia psittacula D; and sequentially graded arrangement of note types (Least Auklet [A. pusilla] and Whiskered Auklet [A. pygmaea]). One species' repertoire (Crested Auklet [A. cristatella]) was composed of a mix of the two forms of display. There were vocal homologies in frequency modulation of notes, arrangement of notes, and note type composition of displays. Our analysis revealed vocal similarities between: (1) two species not normally grouped together (Cassin's and Parakeet auklets): and (2) Whiskered and Crested auklets, which have been suggested previously to be closely related. [ABSTRACT FROM AUTHOR]

We tested predictions concerning the significance of egg neglect for the burrow-nesting seabird Cassin’s auklet (Ptychoramphus aleuticus (Pallas, 1811)) at a colony where endemic Keen’s mice (Peromyscus keeni Merriam, 1897) depredate unattended eggs. A video-camera probe was used to monitor neglect and predation in 32 burrows, and mass loss of incubating adults was measured in 12 separate burrows. Incubating birds lost 8.1% of their body mass over obligate 24 h incubation shifts, suggesting that incubation is costly. In response, most pairs (79%) neglected their egg at least once. As predicted, rates of neglect decreased as incubation progressed, and the costs of neglect increased. Rates of neglect increased during periods of strong winds, which create poor foraging conditions at sea. Contrary to predictions, rates of neglect did not increase when burrows were colder and self-maintenance costs were higher. Neglect was risky in that rates of egg loss by predation increased with frequency of neglect. Increased neglect early in incubation and during periods of poor foraging conditions, despite high rates of predation on neglected eggs, is consistent with the existence of a fitness trade-off between costs and benefits of neglect. [ABSTRACT FROM AUTHOR]

1. Understanding the interactions between different periods of the annual cycle in migratory animals has been constrained by our inability to track individuals across seasons. In seabirds, virtually nothing is known about how diet quality during the non-breeding period, away from the breeding grounds, might influence subsequent reproductive success. 2. We used stable nitrogen (δ15N) and carbon (δ13C) isotopes to evaluate the effects of non-breeding diet quality on the timing of breeding and egg size in a population of Cassin's auklets ( Ptychoramphus aleuticus) breeding on Triangle Island, British Columbia. Adult feathers are grown during two different periods of the annual cycle, which allowed us to estimate diet quality from the previous fall (October–November) and pre-breeding (February–March) period. 3. We found that the estimated proportion of energetically superior copepods ( Neocalanus spp.) in the pre-breeding diet tended to be higher in females that bred earlier and laid larger eggs, whereas energetically poor juvenile rockfish ( Sebastes spp.) were dominant in the pre-breeding diets of females that bred later and laid smaller eggs. We detected no effect of fall diet quality on breeding date or egg size, and no effect of pre-breeding diet quality on breeding date in males. 4. Pre-breeding diet quality was not related to body condition measured 1–2 days after laying, which suggests that females may need to attain a threshold condition before they initiate breeding and successfully rear young. 5. Our results suggest that changes in climatic conditions during the pre-breeding period may have severe consequences for reproductive success by influencing breeding date and egg size. Our work emphasizes the importance of determining how events are linked throughout the annual cycle for understanding the fitness and population dynamics of migratory animals. [ABSTRACT FROM AUTHOR]

We examine how ocean climate variability influences the reproductive phenology and demography of the seabird Cassin's Auklet (Ptychoramphus aleuticus) across ∼2500 km of its breeding range in the oceanographically dynamic California Current System along the west coast of North America. Specifically, we determine the extent to which ocean climate conditions and Cassin's Aukiet timing of breeding and breeding success covary across populations in British Columbia, central California, and northern Mexico over six years (2000-2005) and test whether auklet timing of breeding and breeding success are similarly related to local and large-scale ocean climate indices across populations. Local ocean foraging environments ranged from seasonally variable, high-productivity environments in the north to aseasonal, low-productivity environments to the south, but covaried similarly due to the synchronizing effects of large-scale climate processes. Auklet timing of breeding in the southern population did not covary with populations to the north and was not significantly related to local oceanographic conditions, in contrast to northern populations, where timing of breeding appears to be influenced by oceanographic cues that signal peaks in prey availability. Annual breeding success covaried similarly across populations and was consistently related to local ocean climate conditions across this system. Overall, local ocean climate indices, particularly sea surface height, better explained timing of breeding and breeding success than a large-scale climate index by better representing heterogeneity in physical processes important to auklets and their prey. The significant, consistent relationships we detected between Cassin's Auklet breeding success and ocean climate conditions across widely spaced populations indicate that Cassin's Auklets are susceptible to climate change across the California Current System, especially by the strengthening of climate processes that synchronize oceanographic conditions. Auklet populations in the northern and central regions of this ecosystem may be more sensitive to changes in the timing and variability of ocean climate conditions since they appear to time breeding to take advantage of seasonal productivity peaks. [ABSTRACT FROM AUTHOR]

Sexual selection has been the prevalent explanation for the evolution of birds' elaborate feather ornaments. An overlooked possibility is that feather appendages arose due to a naturally selected sensory function involving sensitivity to pressure or touch to facilitate obstacle avoidance either in flight or on land. Here, we show experimentally that elongated facial feather adornments of whiskered auklets (Aethia pygmaea), a sexually monomorphic crevice-dwelling seabird, have a mechanosensory use for orientation in darkness underground. While navigating inside a lightproof maze simulating the structure and conditions of breeding crevices, whiskered auklets (n = 99) showed a 275% increase in frequency of head bumps in the absence of their protruding feather crest and facial plumes. A weak positive relationship (R = 0.36, P = 0.04) between natural crest length and the frequency of head bumps in the absence of the crest suggested that individuals with longer ornaments depend more on these traits for navigation in the wild. We hypothesize that protruding feathers evolved through a combination of natural selection for sensory function and sexual selection as known for other auklets. More widely, birds inhabiting cluttered environments would benefit from elongated facial plumage that mechanically detects obstacles. [ABSTRACT FROM PUBLISHER]

Abstract: We conducted an integrated study from physics to upper trophic-level predators in the Gulf of the Farallones, California. We hypothesized that decreased zooplankton abundance for upper trophic-level predators in the Gulf of the Farallones during 2004 and 2005 was a response to reduced upwelling-favorable winds and primary production. Based on their trophic ecology, we hypothesized that planktivorous auklets and omnivorous murres will show differential responses to upwelling variability. We examined these hypotheses by analyzing time series on oceanographic variables associated to upwelling and the biological responses at low, mid and high trophic-levels. We found that reduced upwelling-favorable wind was correlated with anomalously high SST and low chlorophyll a concentration from July 2004 to August 2005. During 2005, low chlorophyll concentrations were related to reduced krill abundance in the upper water column and decreased seabird abundance in the vicinity of the breeding colony in the study area. Decreased krill abundance was associated with late timing of nesting and reduced breeding success, with auklets showing a more pronounced response. This study shows how short-term climate variability can affect primary through tertiary productivity, and supports an interpretation of “bottom-up” control of ecosystem dynamics. [Copyright &y& Elsevier]

Within-season variation in life-history parameters is characteristic of long-lived seabirds breeding in dynamic marine environments. Zooplanktivorous Cassin's auklets Ptychoramphus aleuticus breeding in central California feed primarily on euphausiid crustaceans, and switch from provisioning their offspring with Euphausia pacifica early in the nestling period to Thysanoessa spinifera later in the nestling period. I examined the effects of seasonal variation in nestling diet composition and meal mass, and timing of breeding and breeding attempt number (only/first or second breeding attempt) on the growth rate of individual nestlings on Southeast Farallon Island, California. For individual years, there were variable seasonal trends in growth, but no trends were apparent when all years were combined. Along with the predicted seasonal shift in prey use, there was a concurrent decrease in meal mass. In multivariate models, there were significant and positive effects of the mass proportions of E. pacifica and T. spinifera in the diet, meal mass and breeding attempt number on nestling growth, while the effect of hatching date on growth was negative. The relative influence of T. spinifera on growth was stronger than that of E. pacifica, the effects of hatching date on growth were likely dependent on the effects of breeding attempt, and breeding attempt exerted the strongest effect on nestling growth of all parameters examined. These suggest that the seasonal switch in prey use is advantageous (whether intentional or otherwise). Results illustrate the importance of adequate availability of both E. pacifica and T. spinifera to auklets in the Gulf of the Farallones. This study represents a unique approach in the investigation of linkages between individual nestling growth rate and diet and breeding phenology parameters by focusing on a fine temporal scale. [ABSTRACT FROM AUTHOR]

The article discusses the results of a study on the variation in marine distributions of Cassin's Auklets breeding at Triangle Island, British Columbia. To describe the at-sea distributions of the radiomarked birds during their chick-rearing period, the researchers flew high-altitude surveys using radiotelemetry point locations. Results showed that over a three years time from 1999 to 2001, the distribution of the birds in the island vary which was influenced by the distance of their colony and water depth.

1. We performed demographic analyses on Cassin's auklet Ptychoramphus aleuticus, a zooplanktivorous seabird inhabiting the variable California Current System, to understand how temporal environmental variability influences population dynamics. 2. We used capture–recapture data from 1986 to 2002 to rank models of interannual variation in survival, breeding propensity, breeding success, and recruitment. 3. All demographic parameters exhibited temporal variability. Interannual variation in survival was best modelled as a nonlinear function of the winter Southern Oscillation Index (SOI). Breeding propensity was best modelled as a threshold function of local sea surface temperature. Breeding success and recruitment were best modelled with year-dependent annual variation. 4. Changes in the SOI force El Niño/La Niña events, which in turn alter prey availability to seabirds in this system. Demographic responses varied during El Niños/La Niñas. Survival diminished substantially during the 1997–98 El Niño event, while breeding propensity was affected during both the 1992 and 1998 El Niños. Breeding success was reduced during the 1992, 1993, and 1998 El Niños, but was unusually high in 2002. Recruitment was higher at the beginning and end of this time-series. 5. While demographic responses varied interannually, parameter values covaried in a positive fashion, a situation conducive to rapid population change. During the 11 years study period, the Farallon auklet breeding population declined at 6·05 ± 0·80% (SE) per year, a cumulative decline of 49·7%. This study demonstrates how climate variability has influenced key demographic processes for this diminished marine bird population. [ABSTRACT FROM AUTHOR]

We report on the survival of populations of Cassin's Auklet (Ptychoramphus aleuticus) that breed on two oceanic colonies in British Columbia: Triangle Island, near the northern end of the California Current Ecosystem, and Frederick Island to the north in the Alaska Current Ecosystem. We captured and banded birds at both colonies from 1994 to 2000 and analyzed the recovery data with the computer program MARK. Average local adult annual survival (± standard error) was significantly lower (p = 0.0001) on Triangle Island (0.71 ± 0.02) than that on Frederick Island (0.80 ± 0.02), likely a result of poor production in the California Current Ecosystem during the 1990s. Coincident with a strong El Niño event, survival in 1997-1998 fell in unison to the lowest values observed for both colonies (to 0.54 ± 0.05 and 0.64 ± 0.04, respectively, for adults). A common winter environment in the California Current Ecosystem could explain the unified mortality response of both British Columbia populations to an exceptionally poor food period. The seabird colonies in this study occupy key positions in relation to major oceanographic domains and hence provide unique platforms for investigations of marine ecosystem response to ocean climate variability in the Northeast Pacific Ocean. Notre étude traite de la survie des stariques de Cassin (Ptychoramphus aleuticus) qui se reproduisent dans deux colonies océaniques de la Colombie-Britannique, à l'île Triangle, près de l'extrémité nord de l'écosystème du courant de la Californie et à l'île Frederick, plus au nord dans l'écosystème du courant de l'Alaska. Nous avons capturé des oiseaux dans les deux colonies de 1994 à 2000 et les avons munis de bagues; nous avons analysé les données de recapture à l'aide du logiciel MARK. La survie annuelle moyenne locale (± erreur type) est significativement plus faible (p = 0,0001) à l'île Triangle (0,71 ± 0,02) qu'à l'île Frederick (0,80 ± 0,02), probablement à cause de la production réduite dans l'écosystème du courant de la Californie dans les années 1990. Durant un important événement El Niño en 1997-1998, la survie est tombée simultanément au niveau le plus bas observé dans les deux colonies (respectivement à 0,54 ± 0,05 et 0,64 ± 0,04 chez les adultes). Un environnement commun en hiver dans l'écosystème du courant de la Californie pourrait expliquer la réaction semblable de mortalité dans les deux populations de la Colombie-Britannique en réponse à une période exceptionnellement pauvre en nourriture. Les colonies d'oiseaux de mer de cette étude sont dans des positions clés par rapport aux domaines océaniques majeurs et elles fournissent donc des « plates-formes » exceptionnelles pour étudier la réaction des écosystèmes marins à la variabilité du climat océanique dans le nord-est du Pacifique.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

We isolated 17 microsatellite loci in the whiskered auklet (Aethia pygmaea) and tested them for amplification in 48 species from 13 seabird families (including 42 seabirds). Fifteen of these loci were also tested for polymorphism in 38 of the species, which included nine species of Alcinae (four auklets, Atlantic puffin, dovekie, razorbill and two murre species). On the average, nine loci were polymorphic per Alcinae species. [ABSTRACT FROM AUTHOR]

We examined whether radiotransmitters adversely affected the reproductive performance of Cassin's auklets (Ptychoramphus aleuticus) breeding on the California Channel Islands during 1999-2001. We attached external radiotransmitters to 1 partner in 108 Cassin's auklet pairs after nest initiation and used 131 unmarked, but handled, pairs as controls. Compared to alpha chicks raised by radiomarked pairs, alpha chicks raised by unmarked pairs had faster mass growth rates (1.95 ± 0.30 g d-1 vs. 3.37 ± 0.53 g d-1, respectively), faster wing growth rates (2.46 ± 0.10 mm d-1 vs. 2.85 ± 0.05 mm d-1), greater peak fledging masses (1 18.9 ± 3.5 g vs. 148.3 ± 2.4 g), and higher fledging success (61% vs. 90%). Fledging success was reduced more when we radiomarked the male (50% fledged) rather than the female partner (77% fledged). After fledging an alpha chick, unmarked pairs were more likely to initiate a second clutch (radiomarked: 7%; unmarked: 39%) but did not hatch a second egg (radiomarked: 4%; unmarked: 25%) or fledge a second (beta) chick (radiomarked: 4%; unmarked: 18%) significantly more often than radiomarked pairs. We resighted 12 radiomarked individuals nesting during a subsequent breeding season; each bird had shed its transmitter and healed the site of attachment. We suggest caution in using telemetry to evaluate the reproductive performance of alcids, but marking only females may minimize adverse effects. [ABSTRACT FROM AUTHOR]

Planktivorous seabirds readily respond to changes in marine ecosystems and have the ability to integrate information regarding variability in abundance, availability, and community composition of key prey resources. We studied the foraging and breeding ecology of the Cassin's auklet, Ptychoramphus aleuticus (Pallas, 1811), off southern California during three breeding seasons (1999–2001), when large intra- and inter-annual variability occurred in local oceanographic conditions during a prolonged La Niña event. Radio-marked parents used consistent core foraging areas within 30 km of their colony, aggregated in shelf waters (<200 m depth), and occasionally foraged in deeper waters. Parents delivered primarily euphausiids, pelagic larval-juvenile fishes, and minor amounts of cephalopods and other crustaceans. Whereas the euphausiid Thysanoessa spinifera Holmes, 1900 was most important during 1999 and 2001, Euphausia pacifica Hansen, 1911 replaced adult T. spinifera in 2000 after an anomalous eastward inflection of the California Current occurred near the auklets' foraging area. Differences in chick diets, however, did not significantly influence fledging success and growth among first chicks, but the proportion of pairs successfully fledging an alpha chick and initiating a second clutch was exceptional in 1999 (63%) and 2000 (75%), and less in 2001 (7%). We suggest that dietary composition was influenced by modified prey availability driven in part by fluctuations in regional upwelling and circulation. [ABSTRACT FROM AUTHOR]